package com.xwintop.xJavaFxTool.utils;

public class ResourceBundleUtils {

    /**
     * 参考 {@link java.util.Properties} 的 saveConvert() 方法
     */
    public static String toNativeAscii(String theString,
                               boolean escapeSpace,
                               boolean escapeUnicode) {
        int len = theString.length();
        int bufLen = len * 2;
        if (bufLen < 0) {
            bufLen = Integer.MAX_VALUE;
        }
        StringBuilder outBuffer = new StringBuilder(bufLen);

        for(int x=0; x<len; x++) {
            char aChar = theString.charAt(x);
            // Handle common case first, selecting largest block that
            // avoids the specials below
            if ((aChar > 61) && (aChar < 127)) {
                if (aChar == '\\') {
                    outBuffer.append('\\'); outBuffer.append('\\');
                    continue;
                }
                outBuffer.append(aChar);
                continue;
            }
            switch(aChar) {
                case ' ':
                    if (x == 0 || escapeSpace)
                        outBuffer.append('\\');
                    outBuffer.append(' ');
                    break;
                case '\t':outBuffer.append('\\'); outBuffer.append('t');
                    break;
                case '\n':outBuffer.append('\\'); outBuffer.append('n');
                    break;
                case '\r':outBuffer.append('\\'); outBuffer.append('r');
                    break;
                case '\f':outBuffer.append('\\'); outBuffer.append('f');
                    break;
                case '=': // Fall through
                case ':': // Fall through
                case '#': // Fall through
                case '!':
                    outBuffer.append('\\'); outBuffer.append(aChar);
                    break;
                default:
                    if (((aChar < 0x0020) || (aChar > 0x007e)) & escapeUnicode ) {
                        outBuffer.append('\\');
                        outBuffer.append('u');
                        outBuffer.append(toHex((aChar >> 12) & 0xF));
                        outBuffer.append(toHex((aChar >>  8) & 0xF));
                        outBuffer.append(toHex((aChar >>  4) & 0xF));
                        outBuffer.append(toHex( aChar        & 0xF));
                    } else {
                        outBuffer.append(aChar);
                    }
            }
        }
        return outBuffer.toString();
    }

    /**
     * Convert a nibble to a hex character
     * @param   nibble  the nibble to convert.
     */
    private static char toHex(int nibble) {
        return hexDigit[(nibble & 0xF)];
    }

    /** A table of hex digits */
    private static final char[] hexDigit = {
        '0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
    };

}
